QuickTime 7.4, an update provides support for the iTunes rental store, has ran into quite a serious DRM issue with the Adobe After Effects software by preventing it from being able to render video content.  When one attempts to render a video file, they are told that they do not have permission to open the file.  Until the issue is fixed, those who use Adobe After Effects should not upgrade to QuickTime 7.4.  Those who have already put on this version will need to either roll back if they have Time Machine or Pacifist or wait for Apple to release a fix.

To make matters worse, there are several reports of Apple deleting posts on their forum about this issue and so far there is no mention about this issue on Apple's QuickTime 7.4 download page.  The worst affected are been professional video editors, especially those on tight deadlines who upgraded to QuickTime 7.4.  Until Apple releases a fix, a reported workaround in the meantime is to render an image sequence and then use QuickTime professional to export the sequence into a video.  The problem appears to be caused by some process iTunes uses to check for DRM in all open QuickTime movies every 10 minutes. 

So it seems like while Steve Jobs was looking to do away with DRM for music, they seem to be going quite severe on it when it comes to video content.  Another significant users are reporting about QuickTime 7.4 is that it has trouble playing MPEG4 video content, where users are reporting that it plays the audio stream, but not the video.

As iTunes now needs to deal with movie rentals and not just audio and video purchases, it seems like Apple was quick to get out its video rental software without taking the time to at least properly test it with various video formats and different third party software.